Single pilot, the ski guide sits up front, and there are 11 guests in the rear. RH side seats are not used.
The aircraft are stripped of all excess weight, all extra instruments, autopilots, even wiring, etc etc are removed. The standard empty weight is down near 6500-6600 lbs.
I did ski with a fully IFR ship one year .. If I recall correctly, it's EW was just over 7,000 lbs? Thats 35 minutes less fuel ! ( @700 PPH )